Fix invalid tag check for lightweight tags

tagbot/repo.py

@@ -73,9 +73,11 @@ def _invalid_tag_exists(self, version: str, sha: str) -> bool:
         """Check whether or not an existing tag points at the wrong commit."""
         if not git("tag", "--list", version, repo=self._dir()):
             return False
-        expected = f"{sha} refs/tags/{version}^{{}}"
         lines = git("show-ref", "-d", version, repo=self._dir()).splitlines()
-        return expected not in lines
+        # For annotated tags, there are two entries.
+        # The one with the ^{} suffix uses the commit hash.
+        expected = f"{sha} refs/tags/{version}"
+        return expected not in lines and f"{expected}^{{}}" not in lines
 
     def _release_exists(self, version) -> bool:
         """Check whether or not a GitHub release exists."""

test/test_repo.py

@@ -63,6 +63,8 @@ def test_commit_from_tree(git):
         "fedcba refs/tags/v2.3.4^{}",
         "v3.4.5",
         "abcdef refs/tags/v3.4.5^{}",
+        "v4.5.6",
+        "abcdef refs/tags/v4.5.6",
     ],
 )
 def test_invalid_tag_exists(git):
@@ -84,6 +86,13 @@ def test_invalid_tag_exists(git):
             call("show-ref", "-d", "v3.4.5", repo="dir"),
         ]
     )
+    assert not r._invalid_tag_exists("v4.5.6", "abcdef")
+    git.assert_has_calls(
+        [
+            call("tag", "--list", "v4.5.6", repo="dir"),
+            call("show-ref", "-d", "v4.5.6", repo="dir"),
+        ]
+    )
 
 
 def test_release_exists():